/* var car=[];
car[car.length]='a';
car[car.length]='b';
car[car.length]='c';
car[car.length]='d';
console.log(car) */
/* var arr=[];
//索引数组，以>=0的整数作为下标
//关联数组，以字符串作为下标
arr['id']=1;
arr['name']='tao';
arr.sex='男';

console.log(arr); */
var student=[];
student[0]=85;
student[1]=60;
//强调某一元素
student['fitst']=100;
console.log(student)
//只能获取索引数组的长度
console.log(student.length)